Not applicable.
(1) Field of the Invention
The present invention relates to the detection of acoustic energy sources and, more particularly, to a signal processor particularly suited for use in a sonar system for analyzing acoustic energy to determine the identification and the location of the source of acoustic energy.
(2) Description of the Prior Art
Sonar is a system for detection and ranging by means of acoustic energy such as sonic and ultrasonic signals. It takes sound either passively emitted by or actively echoed off of takes sound either passively emitted by or actively echoed off of underwater objects and processes the sound by beam forming and signal processing to provide an auditory scene associated with the underwater objects.
The sonar systems are being continuously updated with improved transducers, sensors and communication links, all providing additional data requiring analysis by the sonar operator. The sonar operator is sometimes presented with a bewildering array of data, but still must make sense of the array in order to perform his/her function. Further improvements in the transducers, sensors and communication links will place a further burden on a sonar operator. It is desired that the sonar system be provided that provides a sonar operator with a comprehensive picture of the undersea environment, but at the same time eases the burden of the sonar operator to easily handle the associated data.
Accordingly, it is a general purpose and object of the present invention to provide for a digital processor particularly suited for use in sonar applications for analyzing acoustic energy to determine the identification and the location of the source of acoustic energy and to do so in a manner to ease the sonar operator""s task.
The digital processor has five (5) stages. The first stage receives beam-formed acoustic energy. The second stage transforms the acoustic energy into a gram, which is representative of the acoustic energy and has time-frequency-space parameters. The third stage receives the gram and extracts elements from the gram and features from the elements. The fourth stage has knowledge supplied from a database defining predetermined elements, regions, and features. The fifth stage receives the elements and the features of the third stage and the supplied knowledge of the fourth stage and derives conclusions based on a comparison between the supplied knowledge and the elements and the features.
It is a further object of the present invention to partially automate the sonar-processing task so as to ease the burden of the operator.
It is a further object of the present invention to provide a signal processor that is easily adapted to further improvements of sensors, transducers, and communication links.